file.c

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/*
 * Copyright 2014 vincent Sanders <vince@netsurf-browser.org>
 *
 * This file is part of NetSurf, http://www.netsurf-browser.org/
 *
 * NetSurf is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * NetSurf is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
/** \file
 * Table operations for files with posix compliant path separator.
 */
 
#include <stdarg.h>
#include <string.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
 
#include "desktop/gui_internal.h"
 
#include "utils/utils.h"
#include "utils/corestrings.h"
#include "utils/url.h"
#include "utils/nsurl.h"
#include "utils/string.h"
#include "utils/file.h"
#include "utils/dirent.h"
 
#ifdef nsamiga
#include "frontends/amiga/os3support.h"
#endif
 
/**
 * Generate a posix path from one or more component elemnts.
 *
 * If a string is allocated it must be freed by the caller.
 *
 * @param[in,out] str pointer to string pointer if this is NULL enough
 *                    storage will be allocated for the complete path.
 * @param[in,out] size The size of the space available if \a str not
 *                     NULL on input and if not NULL set to the total
 *                     output length on output.
 * @param[in] nelm The number of elements.
 * @param[in] ap The elements of the path as string pointers.
 * @return NSERROR_OK and the complete path is written to str
 *         or error code on faliure.
 */
static nserror posix_vmkpath(char **str, size_t *size, size_t nelm, va_list ap)
{
        return vsnstrjoin(str, size, '/', nelm, ap);
}
 
/**
 * Get the basename of a file using posix path handling.
 *
 * This gets the last element of a path and returns it.
 *
 * @param[in] path The path to extract the name from.
 * @param[in,out] str Pointer to string pointer if this is NULL enough
 *                    storage will be allocated for the path element.
 * @param[in,out] size The size of the space available if \a
 *                     str not NULL on input and set to the total
 *                     output length on output.
 * @return NSERROR_OK and the complete path is written to str
 *         or error code on faliure.
 */
static nserror posix_basename(const char *path, char **str, size_t *size)
{
        const char *leafname;
        char *fname;
 
        if (path == NULL) {
                return NSERROR_BAD_PARAMETER;
        }
 
        leafname = strrchr(path, '/');
        if (!leafname) {
                leafname = path;
        } else {
                leafname += 1;
        }
 
        fname = strdup(leafname);
        if (fname == NULL) {
                return NSERROR_NOMEM;
        }
 
        *str = fname;
        if (size != NULL) {
                *size = strlen(fname);
        }
        return NSERROR_OK;
}
 
/**
 * Create a path from a nsurl using posix file handling.
 *
 * @param[in] url The url to encode.
 * @param[out] path_out A string containing the result path which should
 *                      be freed by the caller.
 * @return NSERROR_OK and the path is written to \a path or error code
 *         on faliure.
 */
static nserror posix_nsurl_to_path(struct nsurl *url, char **path_out)
{
        lwc_string *urlpath;
        char *path;
        bool match;
        lwc_string *scheme;
        nserror res;
 
        if ((url == NULL) || (path_out == NULL)) {
                return NSERROR_BAD_PARAMETER;
        }
 
        scheme = nsurl_get_component(url, NSURL_SCHEME);
 
        if (lwc_string_caseless_isequal(scheme, corestring_lwc_file,
                                        &match) != lwc_error_ok)
        {
                return NSERROR_BAD_PARAMETER;
        }
        lwc_string_unref(scheme);
        if (match == false) {
                return NSERROR_BAD_PARAMETER;
        }
 
        urlpath = nsurl_get_component(url, NSURL_PATH);
        if (urlpath == NULL) {
                return NSERROR_BAD_PARAMETER;
        }
 
        res = url_unescape(lwc_string_data(urlpath),
                           lwc_string_length(urlpath),
                           NULL,
                           &path);
        lwc_string_unref(urlpath);
        if (res != NSERROR_OK) {
                return res;
        }
 
        *path_out = path;
 
        return NSERROR_OK;
}
 
/**
 * Create a nsurl from a path using posix file handling.
 *
 * Perform the necessary operations on a path to generate a nsurl.
 *
 * @param[in] path The path to convert.
 * @param[out] url_out pointer to recive the nsurl, The returned url
 *                     should be unreferenced by the caller.
 * @return NSERROR_OK and the url is placed in \a url or error code on
 *         faliure.
 */
static nserror posix_path_to_nsurl(const char *path, struct nsurl **url_out)
{
        nserror ret;
        int urllen;
        char *urlstr;
        char *escpath; /* escaped version of the path */
        char *escpaths;
 
        if ((path == NULL) || (url_out == NULL) || (*path == 0)) {
                return NSERROR_BAD_PARAMETER;
        }
 
        /* escape the path so it can be placed in a url */
        ret = url_escape(path, false, "/", &escpath);
        if (ret != NSERROR_OK) {
                return ret;
        }
        /* remove unecessary / as file: paths are already absolute */
        escpaths = escpath;
        while (*escpaths == '/') {
                escpaths++;
        }
 
        /* build url as a string for nsurl constructor */
        urllen = strlen(escpaths) + FILE_SCHEME_PREFIX_LEN + 1;
        urlstr = malloc(urllen);
        if (urlstr == NULL) {
                free(escpath);
                return NSERROR_NOMEM;
        }
 
        snprintf(urlstr, urllen, "%s%s", FILE_SCHEME_PREFIX, escpaths);
        free(escpath);
 
        ret = nsurl_create(urlstr, url_out);
        free(urlstr);
 
        return ret;
}
 
/**
 * Ensure that all directory elements needed to store a filename exist.
 *
 * @param fname The filename to ensure the path to exists.
 * @return NSERROR_OK on success or error code on failure.
 */
static nserror posix_mkdir_all(const char *fname)
{
        char *dname;
        char *sep;
        struct stat sb;
 
        dname = strdup(fname);
 
        sep = strrchr(dname, '/');
        if (sep == NULL) {
                /* no directory separator path is just filename so its ok */
                free(dname);
                return NSERROR_OK;
        }
 
        *sep = 0; /* null terminate directory path */
 
        if (stat(dname, &sb) == 0) {
                free(dname);
                if (S_ISDIR(sb.st_mode)) {
                        /* path to file exists and is a directory */
                        return NSERROR_OK;
                }
                return NSERROR_NOT_DIRECTORY;
        }
        *sep = '/'; /* restore separator */
 
        sep = dname;
        while (*sep == '/') {
                sep++;
        }
        while ((sep = strchr(sep, '/')) != NULL) {
                *sep = 0;
                if (stat(dname, &sb) != 0) {
                        if (nsmkdir(dname, S_IRWXU) != 0) {
                                /* could not create path element */
                                free(dname);
                                return NSERROR_NOT_FOUND;
                        }
                } else {
                        if (! S_ISDIR(sb.st_mode)) {
                                /* path element not a directory */
                                free(dname);
                                return NSERROR_NOT_DIRECTORY;
                        }
                }
                *sep = '/'; /* restore separator */
                /* skip directory separators */
                while (*sep == '/') {
                        sep++;
                }
        }
 
        free(dname);
        return NSERROR_OK;
}
 
/**
 * default to using the posix file handling
 */
static struct gui_file_table file_table = {
        .mkpath = posix_vmkpath,
        .basename = posix_basename,
        .nsurl_to_path = posix_nsurl_to_path,
        .path_to_nsurl = posix_path_to_nsurl,
        .mkdir_all = posix_mkdir_all,
};
 
struct gui_file_table *default_file_table = &file_table;
 
/* exported interface documented in utils/file.h */
nserror netsurf_mkpath(char **str, size_t *size, size_t nelm, ...)
{
        va_list ap;
        nserror ret;
 
        va_start(ap, nelm);
        ret = guit->file->mkpath(str, size, nelm, ap);
        va_end(ap);
 
        return ret;
}
 
/* exported interface documented in utils/file.h */
nserror netsurf_nsurl_to_path(struct nsurl *url, char **path_out)
{
        return guit->file->nsurl_to_path(url, path_out);
}
 
/* exported interface documented in utils/file.h */
nserror netsurf_path_to_nsurl(const char *path, struct nsurl **url)
{
        return guit->file->path_to_nsurl(path, url);
}
 
/* exported interface documented in utils/file.h */
nserror netsurf_mkdir_all(const char *fname)
{
        return guit->file->mkdir_all(fname);
}
 
/* exported interface documented in utils/file.h */
nserror
netsurf_recursive_rm(const char *path)
{
        DIR *parent;
        struct dirent *entry;
        nserror ret = NSERROR_OK;
        struct stat ent_stat; /* stat result of leaf entry */
 
        parent = opendir(path);
        if (parent == NULL) {
                switch (errno) {
                case ENOENT:
                        return NSERROR_NOT_FOUND;
                default:
                        return NSERROR_UNKNOWN;
                }
        }
 
        while ((entry = readdir(parent))) {
                char *leafpath = NULL;
 
                if (strcmp(entry->d_name, ".") == 0 ||
                    strcmp(entry->d_name, "..") == 0)
                        continue;
 
                ret = netsurf_mkpath(&leafpath, NULL, 2, path, entry->d_name);
                if (ret != NSERROR_OK)
                        goto out;
 
#if (defined(HAVE_DIRFD) && defined(HAVE_FSTATAT))
                if (fstatat(dirfd(parent), entry->d_name, &ent_stat,
                                AT_SYMLINK_NOFOLLOW) != 0) {
#else
                if (stat(leafpath, &ent_stat) != 0) {
#endif
                        free(leafpath);
                        goto out_via_errno;
                }
                if (S_ISDIR(ent_stat.st_mode)) {
                        ret = netsurf_recursive_rm(leafpath);
                        if (ret != NSERROR_OK) {
                                free(leafpath);
                                goto out;
                        }
                } else {
#if (defined(HAVE_DIRFD) && defined(HAVE_UNLINKAT))
                        if (unlinkat(dirfd(parent), entry->d_name, 0) != 0) {
#else
                        if (unlink(leafpath) != 0) {
#endif
                                free(leafpath);
                                goto out_via_errno;
                        }
                }
 
                free(leafpath);
        }
 
        if (rmdir(path) != 0) {
                goto out_via_errno;
        }
 
        goto out;
 
out_via_errno:
        switch (errno) {
        case ENOENT:
                ret = NSERROR_NOT_FOUND;
                break;
        default:
                ret = NSERROR_UNKNOWN;
        }
out:
        closedir(parent);
 
        return ret;
}